CVE-2023-45733: Intel Processors Race Condition Flaw

CVE-2023-45733 Overview

CVE-2023-45733 is a hardware-level race condition affecting certain Intel processors. The flaw resides in microarchitectural logic where concurrent operations are not properly synchronized. An authenticated local user can exploit this timing window to access information that should remain isolated between security boundaries. The vulnerability is tracked under CWE-1298: Hardware Logic Contains Race Conditions. Intel published details in Intel Security Advisory SA-01051. Exploitation requires local access, low privileges, and high attack complexity, limiting practical impact.

Critical Impact
An authenticated local attacker can leverage hardware race conditions to enable partial information disclosure across security domains on affected Intel processors.

Affected Products

Select Intel Processors (refer to Intel SA-01051 for the complete model list)
Systems running firmware predating Intel's coordinated microcode update
Multi-tenant and shared-compute environments using affected silicon

Discovery Timeline

2024-05-16 - CVE-2023-45733 published to the National Vulnerability Database
2026-04-15 - Last updated in NVD database

Technical Details for CVE-2023-45733

Vulnerability Analysis

The vulnerability stems from hardware logic that fails to enforce atomicity during concurrent microarchitectural operations. When multiple execution contexts interact with shared processor resources, a race window opens. An attacker with local code execution can repeatedly trigger this window to observe state that should be isolated. The disclosed data is partial, meaning only a confidentiality fragment is exposed rather than full memory contents. The flaw is classified under CWE-1298, which covers hardware logic with race conditions. Successful exploitation does not modify data and does not impact availability.

Root Cause

The root cause is insufficient synchronization within processor hardware logic. The silicon implementation permits two operations to interleave in a state where one observes intermediate results of another. This violates the security boundary that should isolate authenticated user contexts from privileged or peer-tenant data. Race conditions at the hardware level cannot be fully resolved by software and typically require microcode or firmware updates from the silicon vendor.

Attack Vector

Exploitation requires local access with valid authenticated credentials on the target system. The attacker must execute code that repeatedly drives the processor into the narrow timing window where the race occurs. High attack complexity reflects the precision and repeated attempts needed to land within that window. No user interaction is required. Because the scope changes during exploitation, leaked information may cross from the attacker's context into adjacent security domains. Refer to Intel Security Advisory SA-01051 for processor-specific technical details.

Detection Methods for CVE-2023-45733

Indicators of Compromise

No public indicators of compromise have been published for CVE-2023-45733, and exploitation leaves minimal forensic traces at the operating system level.
Unexpected installation of unsigned or unauthorized local binaries on systems running affected Intel silicon warrants investigation.
Sustained high-frequency execution loops from non-administrative user contexts on shared-compute hosts.

Detection Strategies

Inventory processor models against Intel SA-01051 and flag hosts that lack the corresponding microcode revision.
Monitor for unauthorized local code execution by non-privileged users on systems handling sensitive workloads.
Correlate microcode version telemetry with patch management records to identify drift across the fleet.

Monitoring Recommendations

Collect CPU microcode and BIOS version data through endpoint telemetry and aggregate it for fleet-wide reporting.
Alert when systems boot with outdated microcode after a vendor advisory has been released.
Track local logon events and unusual process creation patterns on multi-tenant hosts.

How to Mitigate CVE-2023-45733

Immediate Actions Required

Apply Intel microcode updates referenced in Intel Security Advisory SA-01051 through OS vendor or OEM channels.
Update system BIOS/UEFI firmware to versions that include the corrected microcode from your hardware manufacturer.
Restrict local code execution privileges on shared and multi-tenant systems running affected processors.

Patch Information

Intel addressed CVE-2023-45733 through microcode updates distributed via OEM BIOS/UEFI firmware releases and operating system microcode packages. Administrators should consult Intel Security Advisory SA-01051 for the affected processor list and corresponding mitigation availability. Linux distributions ship microcode via the intel-microcode package, and Microsoft delivers updates through Windows Update on supported platforms.

Workarounds

Limit interactive and remote local access to trusted accounts only on systems that cannot be immediately patched.
Avoid colocating untrusted workloads on the same physical host until microcode updates are applied.
Enforce least-privilege policies and remove unnecessary local user accounts from sensitive systems.

bash

# Verify and update Intel microcode on Linux
# Check current microcode revision
grep -m1 'microcode' /proc/cpuinfo

# Install or update the microcode package (Debian/Ubuntu)
sudo apt-get update && sudo apt-get install --only-upgrade intel-microcode

# Reload microcode without reboot (where supported)
sudo dmesg | grep -i microcode